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A. BRUNINGHAUS METHOD OF DIRECTLY PRODUCING STEEL Filed Jan. 12, 1925 "8% /fwy MorizeL l charge for the hearth-oven is to be Patented ug' 2:5, 1925.

TED STATES 1,551,465 Pwr-ENT ori-ica ALFRED BRNINGHAUS,

or no1-armonia, GERMAIN.

METHOD 0F DIRECTLY IPBODUCING STEEL.

Application led .Tanuary air is enriched with oxygen.

In this way a product with any desired content or percentage of carbon may be produced according to whether it should leave the `converter asinished steel or in a condition adapted to be employed as a charge roduct for the hearth-oven. k

At the beginning of the process the converter is to be-chargedwith raw iron; later on` the molten mass may be poured out entirely and the converter may be charged Aagain with raw iron, or a remaining part of t' preceding charge l may be left in the converter, so that the rocess may be further carried out with said remaining part.

Thus the i rocess representsit'self in such a manner, t at the bath 's used as a dissolving medium for oxides of iron and carbon, which act one vupon anotherto reduce the iron from the ore. At the same time the bath is heated by the burning of the carbon present in the bath'y and inthe fuel introduced into the latter. For the purpose of raising the temperature, the blastair is enriched with oxygen.

.Upon adding oxides of 'iron the phosho'rus oxidizes simultaneously with the carbon. Therefore the same product can be obtained as in the vraw-iron rocess with phosphorous raw iron, whilst y the well-known. Thomas -process the phosphorus only oxidizes afteroall of the carbon has been removed.

In order to further economize in the consumption of heat, the converter gases are suitably employed for pre-heating and prereducing the ore. For this purpose a rotary oven is used, which works in conjunction with a storage reservoir and with the converter. The action of such pre-reduction is of special importance, as by the enriching of Republic, re-

12, 1925. Serial No. 2,013.

the blastair with oxygen the waste gases are well prepared for the reaction.

The addition of oxides of iron and'carbon in the converter process is known. As new is to .be consideredthekfacts (l) that according to the present invention a oontinuous process is maintained which will.y

commence with the charging of the converter with raw-iron and will be continued by constantly adding ores and-carbon; and (2) that according to the converter process aproduct will be produced similar to that obtained inthe first part of the raw iron ore-process (BertrandThiel-process).

Furthermore the addition ofl oxygen to the blast air is known; but according to the y present invention,- the oxygen is employed for the carrying out of the above named processes; and the oxygen added better prepares lthe converter gas for the reduction of iron ores.

- Without adding oxygen, the addingof larger quantities of ore and substances containing carbon to the bath would be impossile. The bath would become frozen as with saidprocess only a combustion of C to CO takes place and with ordinary -air a suitable temperature could not be obtained. The temperature is theoretically considered to -1 be 17 64 C., but practically it ranges between 1400"-1500o C. Enriching of the blast air.'

with oxygen for the purposeof obtaining a v higher temperature is .therefore strictly required. i

The expenditures of heat for the reduction of the ores are also very considerable.

The quantity of the fuel, which can be introduced, is limited. Therefore in order to avoid useless losses of heat carried ofi' by the escaping nitrogen the air must be enrlched vwith oxygen.

l Furthermore it is known to use the waste gases of the converter for the pre-heating or reductionof ores, but it is new (l) to cause this action to take place in a rotary oven, which works in con]unction with the converter and with a storage vessel; (2) and to 'add oxygen and bon to enrich thev waste gases, so that they become better prepared for the reduction.

fuel containing car- In the drawing a plant isA shown by means of which the new process may be carried .0ut..

The ore togther with the iux are charged into the sha A of the plant and carried `in controlled quantities by the inclined 1'0 tary pipe B into the converter D. C is converter.

In order to charge the converter D, it willbe swung upwardly in the usual manner, Vso that the mouthl of the converter bears against the intermediate plece C. Fuels, which may be in the nature of gas dust or of liquids, are forced into the bath and simultaneously oxygen is introduced intothe blastair. The waste gases permeate the ore within Ithe rotary pi e yB and the shaft A and have a re ucing action thereon.

If the ore is to be brought into the converter, the rotary pipe is set in rotation. Thus it is made possible to bring a large quantity of ore less strongly reduced or a small quantity of ore strongly reduced into the converter. One or the other of these charging methods is used according to how the process is carried out in the converter.

First method: The converter is charged with rawl'iron having a high percentage of phosphorus. It may be supposed that a product is to be obtained which is simllar to the pre-metal employed in the raw iron process with la carbon percentage of about 1% and having a percentage of phosphor as small as possible.

Right at the beginning of the blasting action a strongly oxidized ore and lime is charged by the addition of fuels so that in a known maner the phosphorus of the raw Y iron is oxidized and combined with the scoria. Bv. controlling the quantity of the ore andltlez proportions between the blast air and the fuel the bath will be brought to the required percentage of carbon. If the charge becomes too cold, the blast air is enriched with oxygen.

Second method: By the processvcarried out as above mentioned the phosphorus will be removed from the raw iron or an iron poor in phosphorus is introduced into the converter. The quantity of the bath should bel enlarged to. the greatest degree by the feeding of the ores is to-be regulated in such a. manner, that ores arrive at the converter-afterthey have been reduced to the greatest possible vextent and they are comined in the converter with the bath land become reduced to the finished state.- I'claim:

p 1. The method of making steel or inter-- mediate products direct from iron ore' which comprises feeding a supply of the ore into a bath of molten iron,.introducing from a separate source ca rbonaceous fuel into the bath to distribute asupply of carbon therein, and introducing anvoxygenated gas into the bath. l

2. The method of making steel or intermediate products direct from iron ore which comprises introducing the ore into a .bath of molten iron, forcing a carbonaceous fuel from a source separate from the ore intol the bath to form a carbon solution therein, ndhintroducing an oxygenated gas into the 3. The method of making steel or intermediate products direct froin iron ore which comprises introducing the ore and a `pulverized carbonaceous fuel, from separate sources, into a bath of molten iron, and introducing oxygenated gas into the bath.

4. The method of making steel or intermediate productsdirect 'fromrphosphoric' iron ore; which comprises preparing a-bath' of molten phosphoric iron, introducing into the bath the -ore to be reduced, and a' fuel containing carbon, from separate sources, whereby the oxides of the ore andcarbon are dissolved in the bath, and introducingv oxygenated, airv into the bath.

- 5. The step of pre-reducing iron ores which comprises subjecting such ores to the action of the gases evolved from ,a bath of molten iron vinto which oxygenated gas and iron ore and a carbonaceous fuel from sepa-= rate sources are introduced.

In testimony whereof I have affixed my signature. f ALFRED BRUNINGHAUS. 

